Brake



E. 8. SMITH, JR

BRAKE Filed Aug. 1 21, 1937 EdS.Smith,Jn'

Fig. 2

INVENTOR BY MM ATTORNEY Patented June 27, 19.39

"UNITED STATES PATENT. OFFICE a 2,154,300

no ssmnn, Jr.,

mesne assignments,

of the United States Application August 21,

19 Claims.

This invention relates to brakes and has for an object the provision of a novel braking means capable of providing a smooth acting and powerful braking force in either of two directions. A

,5 further object is to provide a braking means capable of being put into action instantly and with a minimum of work. The brake of my invention is particularly adapted to be placed in action by a light force .acting thru a small dis tance and is also capable of prompt release. My novel braking means is moreover self-actuating in either of opposite directions of movement of the member to be braked, and is simple in construction, as well as highly reliable and efllcient in operation, even where only a limited distance is available for movement of the brake-applying means. Other objects and advantages of the I invention will be hereinafter described and claimed.

In the accompanying drawing: v Fig. 1 is a view in side elevation illustrating an embodiment of my invention. Fig. 2 is a sectional view on line A-A of Fig. 1. Fig. 3 is a view taken on line 13-3 of Fig. 1. Referring to the drawing, my invention is illustrated in conjunction with a brake drum l splined to a shaft 2 for rotation therewith. The brake is shown as comprising three shoes 3, 4, and 5, the shoes 3 and 5 being pivotally connected to shown, be connected by a spring 5 with a stationary bracket I.

An extension 3' of the shoe 3 is shown provided with an adjustable projection I}, secured thereto by screws 9, and connected by pin III to a link H. The latter in turn has a pin l2 which passes ther'ethru and also passes thru one end of a brake controlling member comprising a. pair of parallel arms l3 pinned at their opposite ends to an operating rod H. The pin I! also passes thru slots l5 in a stationary bracket member of the controlling The brake shoe member arms l3.

3n the intermediate shoe 4. Said shoe 4 may, as

comprising a pair of arms IS on opposite sides v 5 is also connected to the con- 55 trolling member arms l3. For this purpose a St. Albans, N. Y., assignor, by to Reconstruction Finance Corporation, Minneapolis, Minn,

a corporation 1937, Serial No. 160,233

ated by a hand lever. Each of the brake shoes 3,

4, and 5 ispreferably provided with inclined projections 2| adapted to engage in similarly inclined grooves 22 in the brake drumi, thereby providing increased frictional engagement with said drum.

Let it now be assumed that the brake is to be applied while the druml is rotating clockwise in Fig. 1. Upon release of the rod ll to the action of spring l9 said rod is pulled to the right by said spring, shifting the attached end of controlling member 13 to the right and drawing the shoes 3 and 5 toward each other and into engagement with the drum. Only a slight movement of member I3 is required for this purpose. The clockwise rotation of the drum I, in conjunction with the engagement of the latter with shoe 3, not only opposes movement of pin l2 upwardly in slot l5, but also draws said pin into engagement with the lower end of the said'slot. Said pin I! now serves as a stationary fulcrum or anchor, about which member l3 turns, bringing the shoes 3, l, and 5 into tighter engagement with the drum ,i. The turning of member l3 about saidpin I2 is caused not only by the force applied thereto by the spring l9 but also by the engagement of the rotating drum l with shoe 5, the clockwise rotation of said drum tending to drag said shoe 5 with it and thereby effect increased application of all of the shoes to said drum.

If, on the other hand, the drum l is rotating counter-clockwise, when member I3 is operated to apply the brake shoes, the engagement of said drum with shoe 5 draws the pin I! to the upper end of slot I8 where said pin becomes the anchor or fulcrum about which the member 13 turns further to apply the shoes more tightly. The counter-clockwise rotation oi drum I and its engagement with shoe 3 assist in this action.

To release the broke, the rod I4 is drawn to the left, against the action of the spring l9. Assuming the drum I to be rotating clockwise, the pull on the shoe 5 is now released and said shoe becomes disengaged from the drum. The end of the intermediate shoe 4 which is connected to shoe 5 now is released and shoe 4 becomes disengaged (its disengagement being hastened by the spring 5) after which shoe 3 becomes disengaged. These actions, while being in sequence, occur almost instanstaneously. II the drum l is rotating counter-clockwise when the rod I3 is drawn to the left-to release the brake, the releasing action occurs ilrst at shoe 3 and then at sh l and 5 in rapid succession.

The speed and promptness of the disengagement of the brake shoes on release is effected by the angles of the wedging contact surfaces 2| and 22 on said shoes and the brake drum. If the angle included between the sides of the wedging projections and grooves is too small the shoes may tend to stick to the drum, and if said angle is too large the braking eflect is less. In the embodiment here illustrated the included angle aforesaid is about 45, which is found to present no sticking tendency and also provides the desired braking effect. It is of course to be understood that the wedge angle referred to may be varied as desired.

It will be seen that the brake of my invention enables a smooth, prompt, and powerful braking force to be applied in either direction of operation of the drum I, that the brake application is as-- sisted by the motion of the drum itself in either direction, and that it is set into action and released by a light force acting thru a small distance, or in other words with a minimum of work. It at the same time is of simple and inexpensive construction, and may be used where only a very limited space is available for operation of the brake controlling member.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications arepossible within the scope of the invention claimed.

I claim:

A 1. A brake for a movable element, said brake comprising a plurality of interconnected shoes, a brake controling member, a stationary member having a pair of slots therein at one side of said element and spaced different distances from said element, means extending into one of said slots and connecting one of said shoes with said brake controlling member, and means extending into the other of said slots and connecting another of said shoes with said brake controlling member.

2. A brake for a movable element, said brake comprising a plurality of interconnected shoes, a brake controlling member, means comprising a pair of projections connecting said member with said-shoes and responsive to movement of said member in one direction for applying said shoes to said element in either direction of operation thereof, one of said projections constituting a fulcrum for said member when said element operates in one direction and the other of said projections constituting a fulcrum for said member when said element operates in the opposite direction.

3. A brake for a movable element, said brake comprising a plurality of interconnected shoes,

while the shoe connected to the other of said projections is dragged by said element to assist in effecting application of the brake, and said other projection constitutes a fulcrum for said member when said element operates in the opposite direction while the shoe connected to the first mentioned projection is dragged by said element to assist in efiecting application of said brake.

4. A brake for an element operable in either of opposite directions, said brake comprising a pair of shoes and means intermediate the shoes of said pair for interconnecting the same, a brake controlling member, means comprising a pair of projections connecting said member with the respective shoes of said pair and responsive to -movement of said member in one direction for applying said shoes to said element, in either direction of operation thereof, one of said projections constituting a fulcrum for said member when said element is operated in one direction and the other of said projections constituting a fulcrum for said member when said element is operated in the opposite direction.

5. A brake for an element operable in either of opposite directions, said brake comprising a pair of shoes and means intermediate the shoes of said pair for interconnecting the same, a brake controlling member, means comprising a pair of projections connecting said member with the respective shoes of said pair, the parts being so constructed and arranged that the projection connecting said member with one of said shoes constitutes a fulcrum of said member when said element operates in one direction while the shoe connected to the other of said projections is dragged by said element to assist in effecting apcomprising a plurality of interconnected shoes,-

a brake controlling member, a stationary member having a pair of slots, a pin extending from one of said shoes into said controlling member and projecting into one of said slots, 5. link con nected to another of said shoes, and a pin extending from said link into said controlling member and projecting into the other of said slots.

'1. A brake for an element operable in either oi opposite directions, said brake comprising a pair of shoes and means intermediate the shoes of said pair for interconnecting the same, a brake controlling member, and connections between said member and said pair of shoes and so constructed and arranged that the connection with-one of said shoes provides a fulcrum for said member in one direction of operation of said member while .the other of said shoes is dragged by said element to assist in applying the brake and the connection between said member and said other shoe of said pair provides a fulcrum for said member in the opposite direction of operation of said member while the first mentioned shoe is dragged by said member to assist in applying the brake.

8. A brake for an element operable in either of opposite directions, said brake comprising a pair of shoes' and means intermediate the shoes of said pair for interconnecting the same, a brake controlling member, and connections between said member and the shoes of said pair and responsive to movement of said member in one direction for applying said shoes to said element in either direction of operation thereof, said connections being so constructed and arranged that one of said pair of shoes assists in applying the brake in one direction of operation of said element and the other of said pair of shoes astion of operation of said element.

9. A brake for an element operable in either 01' opposite directions, said brake comprising shoes, member,

a movable elementysaid brake intercontrolling member, a stationary member aving a pair of slots therein means extending into one of said slots and connecting application 01' the brake, tion constitutes a fulcrum projection is dragged by said element to assist in efl'ecting application of said brake.

12. A brake for a movable element, said brake 01' said slots.

13. A brake for an 01' opposite surfaces is about forty-five degrees.

' the direction of rotation of said rotation of said member.

15. A brake for an element operable in either 16. A brake as set forth in the included angle between claim 15 in which thewedge-shaped 17 A brake for having in combination, opposite directions, a

19. A brake mechanism an element movable in said br means direction of rotation of said I mam-1am. 

